Method and chemical composition for reclaiming of cured elastomer materials

Abstract

Reclaiming cured elastomer material by mixing the cured elastomer as crumbs or chips with a devulcanization-aiding chemical composition, and devulcanizing the cured material by applying a shear-stress deformation to the mixture of the crumbs or chips with a devulcanization-aiding chemical while performing a mechanical disintegration of the cured elastomer into fine-ground crumbs under controllable temperature not exceeding about 90 degrees C., where the chemical composition includes a first agent promoting scission of sulfide bonds of free radicals formed under the shear-stress deformation, which is selected from amines and sulfides and their derivatives, a second agent providing the pre-set acidity during the process inhibiting recombination of sulfide bonds, which is selected from organic acids and their anhydrides, a third agent contributing to fast stabilization of the free radicals, which is selected from oxidants, and a fourth agent promoting redox reaction, which is selected from oxides of metals with variable valence.

What is claimed is: 
     
       1. A method of reclaiming of a cured elastomer material, comprising the steps of:
 a) mixing said cured elastomer in form of crumbs or chips with a devulcanization-aiding chemical composition, and 
 b) devulcanizing said cured material by applying a shear-stress deformation to said mixture of the crumbs or chips with a devulcanization-aiding chemical while performing a mechanical disintegration of the cured elastomer into fine-ground crumbs wherein said chemical composition comprises ingredients as follows:
 (i) a first agent which is selected from the classes of complex compounds formed from amines and sulfides in equimolar ratio; 
 (ii) a second agent which is selected from the classes of organic acids containing an hydroxy radical; 
 (iii) a third agent selected from the class of oxidants, and 
 (iv) a fourth agent selected from oxides of metals with variable valence. 
 
 
     
     
       2. A method according to  claim 1 , wherein a weight percent ratio of said agents ranges as follows: said first agent from about 20 to about 75%; said second agent from about 15 to about 70%; said third agent from about 3 to about 15%; and said fourth agent from about 2 to about 15%. 
     
     
       3. A method according to  claim 1 , wherein ratio of the devulcanization-aiding chemical composition to said cured elastomer is from about 0.015 to about 0.05. 
     
     
       4. A method according to  claim 1 , wherein the organic acids of said second agent are mono- and dibasic organic acids. 
     
     
       5. A method according to  claim 1 , wherein the organic acids of said second agent are acids containing hydroxy radical. 
     
     
       6. A method according to  claim 1 , wherein said third agent are peroxides characterized by easily splitting off atomic oxygen. 
     
     
       7. A method according to  claim 1 , wherein said variable valence metals are iron and manganese. 
     
     
       8. A method according to  claim 1 , wherein the fourth agent comprises oxide Fe 3 O 4 . 
     
     
       9. A method according to  claim 8 , wherein said oxide Fe 3 O 4  is used in a form of fine powder. 
     
     
       10. A method according to  claim 8 , wherein said oxide Fe 3 O 4  is characterized by particles size from about 30 to about 40 mkm. 
     
     
       11. A method according to  claim 1  wherein said chemical composition further comprising a fifth agent selected from the class of polar sorbents. 
     
     
       12. A method according to  claim 11  wherein said fifth agent comprised with a weight percent ratio from about 0 to about 5%. 
     
     
       13. A method according to  claim 1  wherein said cured elastomer material comprising a range of crumbs or chips sizes of few mm. 
     
     
       14. A method according to  claim 13  wherein said cured elastomer material comprising a range of crumbs or chips sizes of about 0.5 mm to 7 mm. 
     
     
       15. A devulcanization-aiding chemical composition for obtaining a curable material from cured elastomer material by applying a mechanical disintegration, said composition comprising at least four agents with following weight percent ratio:
 a first agent from about 20% to about 75% selected from the classes of complex compounds formed from amines and sulfides in equimolar ratio; 
 a second agent from about 15% to about 70% selected from the classes of organic acids containing an hydroxy radical; 
 a third agent from about 3% to about 15% selected from the class of oxidants; and 
 a fourth agent from about 2% to about 15% selected from oxides of metals with variable valence. 
 
     
     
       16. A chemical composition according to  claim 15 , wherein the organic acids of said second agent are mono- and dibasic organic acids. 
     
     
       17. A chemical composition according to  claim 15 , wherein the organic acids of said agent are acids containing hydroxy radical. 
     
     
       18. A chemical composition according to  claim 15 , wherein said fourth agent comprises oxide Fe 3 O 4 . 
     
     
       19. A chemical composition according to  claim 15  further comprising a fifth agent selected from the class of polar sorbents. 
     
     
       20. A chemical composition according to  claim 19 , wherein said fifth agent comprised with a weight percent ratio from about 0 to about 5%.